The minigun, hereinafter referred to as either a minigun or machine gun, is a six-barreled, electrically-driven machine gun capable of fixed firing rates of either 3000 or 4000 rounds per minute. The high rates of fire are achieved by employing barrels that rotate at 500 RPM or 666.67 RPM. The rapid rotation and vibration can cause fasteners that secure a barrel clamp to the barrels to come off if the fasteners are not attached properly. If the fasteners come off while the machine gun is operating, the barrel clamp will be allowed to slip forward and into the line of fire, creating a dangerous and destructive situation.
Historically, the barrel clamp bolt has been known to fall out, allowing the barrel clamp to fall off during operation. Over the years several different configurations have been used, including a self-locking nut, which was eventually replaced by a castellated nut and cotter pin arrangement. The main problem with the self-locking nut was that the locking portion of the nut would wear out due to repeated installation and removal, resulting in the nut backing off the bolt during operation. When attached properly, the improved barrel clamp bolt, castellated nut, and cotter pin arrangement have been shown to adequately fasten the barrel clamp to the barrels; however, the fasteners have been shown to be vulnerable to improper installation. Essentially three failure modes are known. The first occurs when the self-locking nut wears out. When the minigun is fired, the nut eventually backs off, which causes the barrel clamp bolt to fall out and the barrel clamp to slip off. The second occurs when the minigun operator forgets to install the cotter pin in the castellated nut. When the minigun is fired, the nut eventually backs off, which causes the barrel clamp bolt to fall out and the barrel clamp to slip of The third occurs when the barrel clamp bolt is overtightened. When the minigun is fired, the bolt heats up and breaks because it cannot expand. The barrel clamp bolt then falls out, and the barrel clamp slips off.
Therefore, there is a need for a barrel clamp safety retainer that secures a barrel clamp to the barrels even if the barrel clamp's fasteners come off.